Palliative treatment of upper gastrointestinal tract obstruction was undertaken by endoscopic laser therapy in 6 patients with carcinoma of the oesophagus or stomach. All had dysphagia for solids on admission and were considered unsuitable for surgery or radiotherapy. Three were in sites unsuitable for placement of an endoscopic prosthesis. The tumours occluded up to 90 per cent of the lumen (2 squamous and 4 adenocarcinomas). Treatment was carried out under direct vision, the laser wave guide being passed through the biopsy channel of a standard endoscope. Superficial tumour vaporized immediately using energies of 2-10 000 J per session, whereas deeper layers sloughed over the succeeding 2-3 days. Two to six treatments were required to relieve dysphagia and there were no major complications. Quantitative barium studies before and after treatment showed a significant increase in luminal diameter. These patients could eat solid food after treatment and all were able to go home.